Microalgae cultivation and purification of carotenoids using supercritical anti-solvent recrystallization of CO2 + acetone solution

Zeaxanthin is a type of xanthophyll found in carotenoids, which is produced as a food supplement frequently used for human retinal protection. These works investigated growth rate and harvest of the sea water algal species of Nannochloropsis oculata (N. oculata) by in-door and out-door cultivations; stirred ultrasonic acetone extraction of zeaxanthin from; employed column fractionation to obtain zeaxanthinrich elution; and then coupled it with supercritical carbon dioxide anti-solvent (SAS) precipitation to generate the highly pure submicron-sized zeaxanthin. The ultrasonic extract contained 38.2 mg/g of zeaxanthin and then the column elution fractionation increased the zeaxanthin content to 41% (410.3 mg/g) with a recovery of 82.3%. The SAS precipitation at 215 bar, 50 ◦C for 24 min of injection time enhanced the zeaxanthin content to 58% (582.4 mg/g) with a recovery of 67.2%. Experimental results showed that the amount of zeaxanthin increased with total SAS time and feed concentration had an effect of enlarging the precipitates due to agglomeration and accumulation. The SAS precipitation of the column purified algal solution demonstrated a production of micro/nano-sized lamellar particulates that contained high amounts of zeaxanthin

Preparation of highly pure zeaxanthin particles from sea water-cultivated microalgae using supercritical anti-solvent recrystallization

Xanthophylls, including zeaxanthin, are considered dietary supplements with a potentially positive impact on age-related macular degeneration. Using pilot-scale column fractionation coupled with supercritical anti-solvent (SAS) recrystallization, highly pure zeaxanthin particulates were prepared from ultrasonic extracts of the microalgae, Nannochloropsis oculata, grown in sea water. Column partition chromatography increased the concentration of zeaxanthin from 36.2 mg/g of the ultrasonic extracts to 425.6 mg/g of the collected column fractions. A response surface methodology was systematically designed for the SAS process by changing feed concentration, CO2 flow rate and anti-solvent pressure. Zeaxanthin-rich particles with a purity of 84.2% and a recovery of 85.3% were produced using supercritical anti-solvent recrystallization from the column eluate at a feed concentration of 1.5 mg/mL, CO2 flow rate of 48.6 g/min and pressure of 135 bar

Supercritical carbon dioxide anti-solvent precipitation of anti-oxidative zeaxanthin highly recovered by elution chromatography from Nannochloropsis oculata

Zeaxanthin, a kind of xanthophylls, rich in Marigold flowers and a few micro algae, acts as a strong antioxidant capable of protecting human eye-sight from age-related macular degeneration. This study examined elution chromatography coupled with supercritical anti-solvent precipitation applied for generation of zeaxanthin-rich particulates from micro-algal Nannochloropsis oculata species. Crude of the ultrasonic acetone extract subjected to the column fractionation successfully yields a fraction containing 303.02 mg/g (30%) of zeaxanthin with recovery of 90%. Supercritical anti-solvent precipitation of the algal solution at 200 bar and 313 K was used in producing submicron-sized particulates of 50% zeaxanthin. These extracts were subjected to tests of antioxidant capacities in 2,2-diphenyl-2-picrylhydrazyl hydrate free-radical assay and human adult retinal pigment epithelium-19 cells. This work provided a fast and environmental benign process to generate anti-oxidative capable algal micronized powders from the N. oculata

Separation of sight-protecting zeaxanthin from Nannochloropsis oculata by using supercritical fluids extraction coupled with elution chromatography

Microalgae is a potent source of carotenoids and is regarded as functional foods consumed by people worldwide. In this study, supercritical fluid extraction coupled with elution chromatography was employed to recover six carotenoids including zeaxanthin from Nannochloropsis oculata and extraction efficiency of zeaxanthin was determined. The amount of the zeaxanthin (400 mg/g) in the elution fraction increased more than twenty folds from that of the SFE extract (13.17 mg/g). The extracts were subsequently subjected to tests of antioxidant capacities in 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay, 2-2'-azino-bis (3-ethylbenzo- thiazoline-6-sulfonic acid (ABTS)) assay and adult retinal pigment epithelium-19 (ARPE-19) cells. Experimental results demonstrate that other components than zeaxanthin may play a crucial role in the anti-oxidative ability of the extracts from N. oculata. This work provides a useful method to recover bioactive anti-oxidative zeaxanthin from microalgae of N. oculata by using modified supercritical fluids extraction

以可再生吸附劑產製高回收率之藻類玉米黃素保眼原料

一種以可再生吸附劑產製高回收率之藻類玉米黃素保眼原料，尤特指以丙酮（或95%藥用乙醇）為溶劑進行超音波攪拌萃取，再經減壓濃縮後所得之超音波微藻萃取物；最後，再進行微藻超音波萃取，然後經過以PS100樹脂為吸附劑之管柱純化後，最後得到80%以上的回收率且純度在300mg/g至400mg/g之玉米黃素固態產物，為其特徵者

以添加共溶劑的超臨界流體分離濃縮微藻保健成分

一種以添加共溶劑的超臨界流體分離濃縮微藻保健成分，尤特指利用共溶劑修飾的超臨界流體萃提微藻的類葫蘿蔔素成份，主要是以預浸式及連續式添加不同比例乙醇共溶劑在超臨界二氧化碳中，所得微藻萃出物的結果顯示，乙醇的連續添加比例是影響微藻類葫蘿蔔素萃取效率與濃度的主要變因。如以350bar、323K及11.7wt%總乙醇添加比例的超臨界流體，每克萃取物中含有8.30毫克的總類葫蘿蔔素；但當乙醇添加比例達16.7%時，雖有較高的萃取效率74.7%，但是每克萃取物的類葫蘿蔔素量卻降至7.61毫克。顯示如要得到高萃取效率與高類葫蘿蔔素含量的微藻萃出物，乙醇的添加比例應有最適值

以添加共溶劑的超臨界流體分離濃縮微藻之類葫蘿蔔素的方法

一種以添加共溶劑的超臨界流體分離濃縮微藻之類葫蘿蔔素的方法，，以預浸式及連續式添加不同比例乙醇共溶劑在超臨界二氧化碳中，所得微藻萃出物的結果顯示，乙醇的連續添加比例是影響微藻類葫蘿蔔素萃取效率與濃度的主要變因。如以350bar、323K及11.7wt%總乙醇添加比例的超臨界流體，每克萃取物中含有8.30毫克的總類葫蘿蔔素；但當乙醇添加比例達16.7%時，雖有較高的萃取效率74.7%，但是每克萃取物的類葫蘿蔔素量卻降至7.61毫克。顯示如要得到高萃取效率與高類葫蘿蔔素含量的微藻萃出物，乙醇的添加比例應有最適值